Various bistatic intrusion detectors exist for detecting the intrusion of persons or equipment across a line; e.g. a border or area perimeter. Exemplary detectors are discussed in the following U.S. Pat. Nos.
2,203,807 PA0 3,237,105 PA0 3,618,083 PA0 3,618,091 PA0 3,696,368 PA0 3,877,002 PA0 4,605,922 PA0 4,697,184
A bistatic detector is comprised of a microwave transmitter and receiver, which, when deployed, are typically spaced from one another by several hundred feet. Processor means monitors the microwave energy received by the receiver and interprets a signal variation greater than a certain threshold as constituting an intrusion or alarm condition.
Applicant's parent application describes an intrusion detection system employing multiple bistatic links and wireless means for remotely interrogating each link to provide alarm information at a central station. The preferred embodiment described therein includes a plurality of identical sector sets, each forming a pair of bistatic microwave links. Each sector set is comprised of a sector module and first and second transmit modules which together form left and right bistatic links. The sector module includes oppositely oriented first and second receive antennas and supporting electronics. Each of the sector and transmit modules is physically configured so as to be readily remotely deployed, each module including a self contained battery and solar charging panel. In operation, each transmit module transmits a microwave carrier with encoded status information over its link to the associated sector control module. The status information is indicative of operating conditions (i.e. normal or fault) at the transmit module such as tampering, low battery voltage, etc. The transmitted carrier and status information is received at the sector module and processed and decoded to yield both alarm and status data.